We are contributing to NTP technical reports of rodent bioassays on cobalt, vinylidene chloride (an intermediate in polymer production), tetrabromobisphenol-A (a flame retardant), glycidamide, green tea extract, bromodichloroacetic acid (a water disinfection byproduct) that will be reviewed by the NTP Board of Scientific Counselors in the fall and early next spring. We also participated in study design committees for over 12 chemicals that will be tested by the NTP. We published papers in the scientific literature on chemicals that were recently tested by the NTP: hexavalent chromium and Gingko biloba. The NTP's extensive testing program provides opportunities to investigate patterns across studies. We contributed to a multi-study evaluation of rat pancreatic islet cell tumors which showed that protein expression in these tumors was similar to that found in humans. The immunohistochemical characterization of these tumors also provided indications of possible pathways for carcinogenesis in islet cells. We continued to provide advice on statistical methods for evaluating alternative methods for NTP's toxicity and carcinogenicity testing. These include: 1) providing advice about the analysis of high throughput data from cell-based assays of chemicals selected by the NTP, that were generated by the NIH Chemical Genomics Center, 2) providing advice about applying the up-and-down procedure to dermal toxicity testing, and 3) providing advice about how to combine batteries of in vitro test results to predict in vivo results.